Various embodiments of an analog-to-digital (A/D) device are described herein, with the A/D device using at least a comparison unit, a comparative operation control circuit, a delay circuit, and a successive operation control circuit arranged so as, it may, among other things, mitigate conversion errors that may be due to differences in properties of circuit elements therein. And the A/D device may be implemented in, among other things, a signal processing device.